My Firefox Dev Edition just updated to 89 b1 today. The screen was blank, the new tab button and no buttons are working. None of the menu items work except the About Firefox which just keeps showing the Restart To Update button. If I click it, it just loads the same blank page again and same issue. I uninstalled and downloaded b2 from the website and still same exact issues. I'm running macOS 11.3 RC which was released today.